In controlling pollution, which action should be taken after all dirty ballast has been transferred to the slop tank and prior to discharge through the oily water separator?

Correct Answer: Option D — The slops should be allowed time to settle.

Under MARPOL Annex I and USCG pollution regulations, decanting requires allowing the slop tank contents sufficient time to settle. This gravity separation ensures the oil rises to the top, allowing clean water from the bottom to be safely discharged through the oily water separator.